Thank you, Boki, for the tip and reference.
Here is what I did. I am not at a place where I can test the code, but when I do and if needs changes I will return to keep this post's documentation correct.
again, this is in the OnMouseMove event
WITH GridView2 DO
BEGIN
RowNum := NxReportGridView61.GetCellAtPos(Point(x,y)).Y;
ColNum := NxReportGridView61.GetCellAtPos(Point(x,y)).X;
Col6 := NxReportGridView61.GetColumnAt(x,y, gaHeader);
ACellRect := NxReportGridView61.GetCellRect(x,y);
IF (ColNum > -1) AND (RowNum > -1)
and CellExists(ColNum, RowNum)
and (Col6 is TNxTextColumn6) THEN
BEGIN
// limit hints to columns and rows that actually exist and the text doesn't fit
// the cell
AView := NxReportGridView61.UpdateCellView(x, y, ACellRect);
if not AView.CanFitText then
begin
IF TNxTextColumn6(Col6).WrapKind <> TNxWrapKind(wkWordWrap) THEN
BEGIN
Cell[ColNum, RowNum].Hint := Cell[ColNum, RowNum].AsString
END
ELSE
BEGIN
Cell[ColNum, RowNum].Hint := ''
END;
end;
end;